A new method in highway route design: joining circular arcs by a single C-Bézier curve with shape parameter
- 124 Downloads
We constructed a single C-Bézier curve with a shape parameter for G2 joining two circular arcs. It was shown that an S-shaped transition curve, which is able to manage a broader scope about two circle radii than the Bézier curves, has no curvature extrema, while a C-shaped transition curve has a single curvature extremum. Regarding the two kinds of curves, specific algorithms were presented in detail, strict mathematical proofs were given, and the effectiveness of the method was shown by examples. This method has the following three advantages: (1) the pattern is unified; (2) the parameter able to adjust the shape of the transition curve is available; (3) the transition curve is only a single segment, and the algorithm can be formulated as a low order equation to be solved for its positive root. These advantages make the method simple and easy to implement.
Key wordsTransition curve C-Bézier curve Monotone curvature Shape parameter
Unable to display preview. Download preview PDF.
- Baass, K.G., 1984. The use of clothoid templates in highway design. Transp. Forum, 1(1):47–52.Google Scholar
- Habib, Z., 2004. Spiral Function and Its Application in CAGD. PhD Thesis, Kagoshima University, Japan.Google Scholar
- Hartman, P., 1957. The highway spiral for combining curves of different radii. Trans. Am. Soc. Civ. Eng., 122:389–409.Google Scholar
- Polya, G., Szego, G., 2004. Problems and Theorems in Analysis II: Theory of Functions, Zeros, Polynomials, Determinants, Number Theory, Geometry. Springer, New York, p.36–51.Google Scholar